starting work on a demo
Checkpoint adding textures.  Textures apparently load and don't crash.  But, wtf is up with java and signed bytes?!?
Loading textures works.  add :textures ["img1.jpg" "img2.png"] to start call.  So, issue #3 is nearly finished.  Just a bit of cleanup to go.

Also, fix #11 to check for file existence before starting.